The present invention relates to information acquisition from, and control of, remotely located scanners, and use of such scanners for collection of news, traffic (e.g., traffic incident reporting), weather, police, fire and rescue activities, and the like.
Information gathering organizations are always looking for methods to improve the information gathering process. Technology has provided many new tools and opportunities for such organizations. The ability to monitor public airwaves has provided a valuable tool to alert and inform an organization of possible incidents and events. As technology progressed, Radio Spectrum Frequency scanners became a basic tool to collect information. A scanner or scanning radio is a specialized radio receiver designed to tune a wide range of frequencies. Frequencies are stored in channels and selectively scanned or the scanner can search through an entire frequency range. Scanner receivers differ in contrast to radio communication receivers in that they usually do not have a variable frequency oscillator (VFO) and they usually do not cover the high frequency (HF) 3-30 MHz spectrum. Scanners usually scan and search much faster than regular receivers.
Scanners allow a user to obtain information from organizations such as Police, Fire-Rescue and Ambulance. Dispatching activities can inform a listener of possible issues that affect a community and impact activity, such as travel. One problem that occurs when trying to monitor radio broadcast activities is the limited distance that these broadcast signals cover. Signals are shared and transmission power is limited to avoid problems with the shared signals. To extend the reach of an information gathering organization, satellite collection agents were employed to gather information not physically present at a primary gathering office.
More advanced applications of radio frequency spectrum scanners placed a scanner into a remote location and used audio links to forward sound to a central monitoring facility. This solution provided a blind solution making it difficult to attribute the sound of a transmission to the transmitting entity. Being able to see a scanner display allows a user to cover many frequencies and view the frequency when a transmission is heard, thereby associating the transmission source. In addition to the difficulty with the blind nature of a remote audio solution, any tuning or changes that were required to the remote unit required someone to physically visit the unit in the field. Real-time interaction is extremely valuable, but not available to any of these legacy solutions. If an important transmission is heard, locking into a frequency allows a user to acquire addition information that may be lost if scanning resumes. Scanning of frequency banks is likely to occur when control is not present.
Integration of audio, video and control are desirable to maximize the value of a remotely deployed unit. Some existing products provide a limited ability to meet this need. For example, products are available which allow a scanner to be controlled by a personal computer (PC) located physically adjacent to the scanner and connected to an RS-232C port of the scanner via a hardwired cable (PC interface). Software executing on the PC presents a simulated display of the scanner and the user can control selected functions of the scanner by interacting with the simulated scanner display. One such product is software associated with the Model No. IC-PCR100 and PCR1000 scanners from Icom Inc., Osaka, Japan. Another product is third-party software for the Model Bearcat BC780XLT Trunk Tracker III scanner from Uniden, Fort Worth, Tex. The third-party software is WinScan® 780, Version 1.0 Scanner Control Software, available from Pozilla Software Corp. Neither of these products, nor the associated software, allow for remote user capabilities. When using these PC interface products, the external speaker output jack of the scanner is connected to a speaker or microphone input of the PC, thereby allowing the scanner's audio to be played in real-time through the speakers of the PC. This scheme provides no ability to play the audio at a location remote from the PC.
Many software and hardware manufacturers produce audio and streaming products. Microsoft produces Windows Media, and RealNetworks, Inc., Seattle, Wash., produces a plurality of streaming audio products. The current methods of streaming audio suffer from buffering and time delays, as discussed in more detail below. Hardwired audio links have also been employed to provide blind solutions.
FIG. 15 shows a typical prior art architecture for streaming audio and video data. Functional responsibilities are highlighted underneath each of the components. FIG. 16 provides an overview of the processing requirements to create and distribute an audio stream in accordance with the prior art. More specifically, FIG. 15 provides an overview of the functions performed on an audio or video stream as a stream is prepared and delivered to clients or consumers of the data stream. The processing requirements for both audio and video are practically identical, except that video produces a significantly larger data stream.
Referring to FIG. 15, streaming data is broadcast from a head-end or source (1401 through 1405). The most common form of stream is read from a file, which contains a previously encoded data stream. Streaming audio from a real-time source involves real-time encoding of audio or video source. Once encoded, a stream is compressed to optimize network bandwidth. Compression requires both time and processing cycles. After a data stream is compressed, it is prepared for broadcasting (1405). Broadcasting a data stream allows many users to attach to a data stream (1406 through 1408). A distribution infrastructure is built proportional to the number of concurrent users receiving the data stream (1404 and 1405). Streaming audio is the primary method of distributing audio on the Internet today.
Streaming audio, especially in real-time, is constrained by parameters associated to streaming technology. Streaming data operates most efficiently on low overhead protocols, which reduces head end resources and network bandwidth requirements. Common distribution protocol leverages User Datagram Protocol (UDP), Multicast, or other broadcast technologies to deliver data over a stateless and connectionless network transport. The combination of real-time encoding, broadcasting to many users, and connectionless or lightweight data delivery has several adverse effects on an audio or video stream.
Buffering of streaming audio is problematic when applied to certain applications that have real-time needs. An audio stream is buffered to maximize compression. Compression is more effective when applied to larger data sets. To achieve compression, the encoding source buffers data to achieve better compression. The client or listener also buffers a data stream. Client buffering addresses network delivery issues such as out of sequence packets and network throughput issues. While buffering provides an enhanced experience for the average Internet user, buffering introduces a serious problem for a control-based system. Buffering delays transmission, which introduces a delay in the control feedback loop. For example, audio systems such as RealAudio® (a product of RealNetworks, Inc., Seattle, Wash.) use a buffering system to give the illusion of real-time transfer. The software in such audio systems delay reproducing a transmission for a human perceptible period of time in the order of seconds to build a buffer of data. This process ensures that a smooth reproduction will occur even if there is a delay in the transmission link.
The only conventional way to coordinate audio, video and control of a scanner in real time is to have personnel local to the scanner itself. In addition, scanning radio broadcasts covering large number of public agencies requires several difference technologies, including legacy analog systems, trunk systems and new digital transmission methods. The majority of the scanner market is focused on non-commercial applications such as the hobbyist. Thus, there is a significant problem in developing real-time remote control scanner solutions that work across such various platforms. In sum, prior approaches and technologies continue to have deficiencies, especially in processing information that requires real-time control and other remote interaction, as well as real-time listening of audio.